NASA has recently released an image over a billion pixels of our closest galactic neighbor within its local group, the Andromeda Galaxy. That’s over 4 gigs of data. Now, the part of the Andromeda Galaxy that you see in the video below contains approximately 100 billion stars and spans farther than 40,000 light years. In order to create this video, davechuk took 411 Hubble pictures and created a mosaic:
How much do we know about the Andromeda Galaxy?
Well what we do know is that it is over 2.5 million light years away from the Milky Way, so we won’t be seeing it anytime soon. It’s been around for 9 billion years, has 1 trillion stars, and it’s mass is around 1,230 billion M☉ (This symbol represents solar mass, which is used to determine the masses of stars, clusters, nebulae and of course galaxies). All in all, this tells us that the Andromeda Galaxy is pretty damn big.
How long have we known about this galaxy? Well, a Persian astronomer named And al-Rahman al-Sufi wrote about it in his work titled Book of Fixed Stars around the time period of 964 whilst describing the galaxy as a small cloud. It wasn’t until much later that Charles Messier catalogued the Andromeda Galaxy as M31 in 1764, and it wasn’t until 1887 that Isaac Roberts would take the first photograph of our closest spiral neighbor. At that time we believed that M31 was within our galaxy and was a nebula, or potentially a solar system being formed. This was widely believed until the Great Debate of 1920, and while many people had come forth with evidence on the distance of M31 it wasn’t until 1925 when Edwin Hubble used the Hooker Telescope, which was 100 inches long (2.5 meters), that they were able to determine the distance of M31.
In case all that information doesn’t put you in a stupor, in about 3.75 billion years the Milky Way Galaxy and the Andromeda Galaxy are going to collide and become a new galaxy together. The Andromeda Galaxy is moving towards the Milky Way at around 68 miles per second. Of course your next thought is, “But won’t all the stars and planets collide in some big giant explosion?” The answer to that question is: highly unlikely. Sure the occasional star might collide with another one but there is so much space into between the stars in each galaxy that the chances of them colliding are minute. When they do merge, scientists expect the two galaxies to become either a giant elliptical galaxy or a large disk galaxy. So who is ready to party when the galaxies collide? Anyone?